1. Field of the Invention
The present invention relates to a method and apparatus for confirming the charge amount and degradation state of a battery, a storage medium, an information processing apparatus and an electronic apparatus that, based on a battery's charge and discharge characteristics, enables the charge amount and degradation state of the battery to quickly be estimated. The “battery” as used herein encompasses batteries that include various active materials and/or rated voltages that can be repeatedly charged and discharged.
2. Description of the Prior Art
To some degree, a battery has the property of reverting to its original charge amount when discharge is halted. This has made it difficult to estimate accurately the charge amount and degradation state of a battery by simply measuring the battery voltage and discharge current. If it is known that the discharge voltage and current are extremely weak, it can be determined that the battery is at the end of its life. In general, in the case of batteries used in electric equipment, the discharge voltage and/or the discharge current is measured, and if it is found to have fallen below a certain level, that fact is shown on the LCD display of the equipment as a prompt to replace the battery. The life of a battery can be estimated to some extent by measuring the capacity of a battery that has been charged and/or discharged for an extended period (around one or two hours).
However, since a battery uses chemical reactions to generate electricity, batteries having the same active material or rating can have different charge amounts and degradation state at any particular time, depending on the state in which each battery is kept and used, and the temperature and other environmental factors. As a result, even if the LCD display indicates that a battery has around half its charge or is half degraded, it is not unusual for the battery to suddenly become unusable. It has therefore been considered that it is not possible to display accurately, in a short time, the remaining charge and the degradation state of a battery.
This inability to accurately gauge the remaining charge and degradation state of a battery has made it difficult to determine whether a battery is new or is one that has been repeatedly charged and discharged. Moreover, new batteries sometimes include ones that are degraded and have only a small charge amount, even after being charged. If someone with bad intentions buys a battery and repeatedly charges and discharges it, then tells the seller that it is defective although in fact it has just been degraded, the seller finds it difficult to refute the claim.
An object of the present invention is therefore to provide a method and apparatus for confirming the charge amount and degradation state of a battery, a storage medium, an information processing apparatus, and an electronic apparatus that, by measuring different charge and discharge characteristics at a plurality of time points over a short time period, make it possible to stochastically measure the remaining charge amount and degradation state of the battery substantially accurately.